Parliamentary sovereignty is often seen as a central element in the British constitution, although its extent is contested. It means that an Act of Parliament is the highest form of law, but also that "Parliament cannot bind itself".
https://en.wikipedia.org/wiki/Constitution_of_the_United_Kin...
A fringe group of modern day commonwealth citizens construct quite elaborate fantasies based on that:
https://ukhumanrightsblog.com/2020/12/04/magna-carta-and-fre...
A lot of things in modern democracies, or even older ones (like the US's federal constitution) are really there to act as roadblocks and prevent a simple majority of voters from electing some shitty politicians who make wild changes in the law. It's a bit like that scene in "Alien" when Sigourney wants to blow up the Nostromo, and has to go through a ridiculous process of flipping switches and raising and turning and lowering some metal cylinders inside a control panel in the floor: blowing up the ship doesn't really need all that stuff, but it's just there to make it hard to do quickly and easily.
I wonder if this creates a feeling among voters that it is OK or even desirable to vote for batshit politicians, because they'll be constrained by the constitution and "nothing ever changes anyway".
And then those politicians decry the constraining checks and balances as the "deep state" or "the blob".